From: Matthew Wilcox <willy@linux.intel.com>
To: Luben Tuikov <ltuikov@yahoo.com>
Cc: Greg KH <greg@kroah.com>,
linux-usb@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: [PATCH] [USB] UAS: eliminate infinite loop; add debug print
Date: Mon, 8 Nov 2010 06:24:56 -0500 [thread overview]
Message-ID: <20101108112456.GI4173@linux.intel.com> (raw)
In-Reply-To: <106187.30360.qm@web31802.mail.mud.yahoo.com>
On Fri, Oct 29, 2010 at 05:33:19PM -0700, Luben Tuikov wrote:
> Eliminate an infinite loop whereby the SCSI layer
> would reissue a command (which would be failed by
> the driver) ad infinitum. (Invariably due to the
> driver's profuse use of the
> SCSI_MLQUEUE_DEVICE_BUSY returned result in its
> queuecommand() method.)
>
> Also add a debug option and a few debug prints.
Why have you added your own debug scheme instead of using dev_dbg?
You've made a lot of other random whitespace changes too.
I'll pick through this and see what I like in it.
> Signed-off-by: Luben Tuikov <ltuikov@yahoo.com>
> ---
> drivers/usb/storage/Kconfig | 10 ++++
> drivers/usb/storage/Makefile | 4 ++
> drivers/usb/storage/uas.c | 102 +++++++++++++++++++++++++++--------------
> 3 files changed, 81 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/usb/storage/Kconfig b/drivers/usb/storage/Kconfig
> index 49a489e..eb9f6af 100644
> --- a/drivers/usb/storage/Kconfig
> +++ b/drivers/usb/storage/Kconfig
> @@ -185,6 +185,16 @@ config USB_UAS
>
> If you compile this driver as a module, it will be named uas.
>
> +config USB_UAS_DEBUG
> + bool "Compile in debug mode"
> + default n
> + depends on USB_UAS
> + help
> + Compiles the uas driver in debug mode. In debug mode,
> + the driver prints debug messages to the console.
> +
> + If unsure, say 'N'.
> +
> config USB_LIBUSUAL
> bool "The shared table of common (or usual) storage devices"
> depends on USB
> diff --git a/drivers/usb/storage/Makefile b/drivers/usb/storage/Makefile
> index fcf14cd..16715ab 100644
> --- a/drivers/usb/storage/Makefile
> +++ b/drivers/usb/storage/Makefile
> @@ -10,6 +10,10 @@ ccflags-y := -Idrivers/scsi
> obj-$(CONFIG_USB_UAS) += uas.o
> obj-$(CONFIG_USB_STORAGE) += usb-storage.o
>
> +ifeq ($(CONFIG_USB_UAS_DEBUG),y)
> + EXTRA_CFLAGS += -DUAS_DEBUG
> +endif
> +
> usb-storage-y := scsiglue.o protocol.o transport.o usb.o
> usb-storage-y += initializers.o sierra_ms.o option_ms.o
>
> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
> index 48dc2b8..ef6e707 100644
> --- a/drivers/usb/storage/uas.c
> +++ b/drivers/usb/storage/uas.c
> @@ -21,6 +21,14 @@
> #include <scsi/scsi_host.h>
> #include <scsi/scsi_tcq.h>
>
> +#define uas_printk(fmt, ...) printk(KERN_NOTICE "uas: " fmt, ## __VA_ARGS__)
> +
> +#ifdef UAS_DEBUG
> +#define UAS_DPRINTK uas_printk
> +#else
> +#define UAS_DPRINTK(fmt, ...)
> +#endif
> +
> /* Common header for all IUs */
> struct iu {
> __u8 iu_id;
> @@ -128,6 +136,7 @@ static void uas_do_work(struct work_struct *work)
> {
> struct uas_cmd_info *cmdinfo;
> struct list_head list;
> + int res;
>
> spin_lock_irq(&uas_work_lock);
> list_replace_init(&uas_work_list, &list);
> @@ -136,8 +145,10 @@ static void uas_do_work(struct work_struct *work)
> list_for_each_entry(cmdinfo, &list, list) {
> struct scsi_pointer *scp = (void *)cmdinfo;
> struct scsi_cmnd *cmnd = container_of(scp,
> - struct scsi_cmnd, SCp);
> - uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_KERNEL);
> + struct scsi_cmnd, SCp);
> + res = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_KERNEL);
> + UAS_DPRINTK("%s: cmd:%p, res:%d, state:0x%x\n", __FUNCTION__,
> + cmnd, res, cmdinfo->state);
> }
> }
>
> @@ -198,13 +209,15 @@ static void uas_sense_old(struct urb *urb, struct scsi_cmnd *cmnd)
> }
>
> static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
> - unsigned direction)
> + unsigned direction)
> {
> struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
> int err;
>
> cmdinfo->state = direction | SUBMIT_STATUS_URB;
> err = uas_submit_urbs(cmnd, cmnd->device->hostdata, GFP_ATOMIC);
> + UAS_DPRINTK("%s: cmd:%p, err:%d, state:0x%x\n", __FUNCTION__,
> + cmnd, err, cmdinfo->state);
> if (err) {
> spin_lock(&uas_work_lock);
> list_add_tail(&cmdinfo->list, &uas_work_list);
> @@ -222,7 +235,8 @@ static void uas_stat_cmplt(struct urb *urb)
> u16 tag;
>
> if (urb->status) {
> - dev_err(&urb->dev->dev, "URB BAD STATUS %d\n", urb->status);
> + dev_err(&urb->dev->dev, "%s: URB BAD STATUS %d\n",
> + __FUNCTION__, urb->status);
> usb_free_urb(urb);
> return;
> }
> @@ -259,6 +273,14 @@ static void uas_stat_cmplt(struct urb *urb)
> static void uas_data_cmplt(struct urb *urb)
> {
> struct scsi_data_buffer *sdb = urb->context;
> +
> + if (urb->status) {
> + dev_err(&urb->dev->dev, "%s: URB BAD STATUS %d\n",
> + __FUNCTION__, urb->status);
> + usb_free_urb(urb);
> + return;
> + }
> +
> sdb->resid = sdb->length - urb->actual_length;
> usb_free_urb(urb);
> }
> @@ -339,7 +361,7 @@ static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
> memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
>
> usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
> - usb_free_urb, NULL);
> + usb_free_urb, NULL);
> urb->transfer_flags |= URB_FREE_BUFFER;
> out:
> return urb;
> @@ -355,23 +377,26 @@ static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
> */
>
> static int uas_submit_urbs(struct scsi_cmnd *cmnd,
> - struct uas_dev_info *devinfo, gfp_t gfp)
> + struct uas_dev_info *devinfo, gfp_t gfp)
> {
> struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
> + int res;
>
> if (cmdinfo->state & ALLOC_STATUS_URB) {
> cmdinfo->status_urb = uas_alloc_sense_urb(devinfo, gfp, cmnd,
> cmdinfo->stream);
> if (!cmdinfo->status_urb)
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + return -ENOMEM;
> cmdinfo->state &= ~ALLOC_STATUS_URB;
> }
>
> if (cmdinfo->state & SUBMIT_STATUS_URB) {
> - if (usb_submit_urb(cmdinfo->status_urb, gfp)) {
> + res = usb_submit_urb(cmdinfo->status_urb, gfp);
> + if (res) {
> scmd_printk(KERN_INFO, cmnd,
> - "sense urb submission failure\n");
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + "sense urb submission failure (%d)\n",
> + res);
> + return res;
> }
> cmdinfo->state &= ~SUBMIT_STATUS_URB;
> }
> @@ -381,15 +406,17 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
> devinfo->data_in_pipe, cmdinfo->stream,
> scsi_in(cmnd), DMA_FROM_DEVICE);
> if (!cmdinfo->data_in_urb)
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + return -ENOMEM;
> cmdinfo->state &= ~ALLOC_DATA_IN_URB;
> }
>
> if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
> - if (usb_submit_urb(cmdinfo->data_in_urb, gfp)) {
> + res = usb_submit_urb(cmdinfo->data_in_urb, gfp);
> + if (res) {
> scmd_printk(KERN_INFO, cmnd,
> - "data in urb submission failure\n");
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + "data in urb submission failure (%d)\n",
> + res);
> + return res;
> }
> cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
> }
> @@ -399,15 +426,17 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
> devinfo->data_out_pipe, cmdinfo->stream,
> scsi_out(cmnd), DMA_TO_DEVICE);
> if (!cmdinfo->data_out_urb)
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + return -ENOMEM;
> cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
> }
>
> if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
> - if (usb_submit_urb(cmdinfo->data_out_urb, gfp)) {
> + res = usb_submit_urb(cmdinfo->data_out_urb, gfp);
> + if (res) {
> scmd_printk(KERN_INFO, cmnd,
> - "data out urb submission failure\n");
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + "data out urb submission failure (%d)\n",
> + res);
> + return res;
> }
> cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
> }
> @@ -416,15 +445,16 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
> cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, gfp, cmnd,
> cmdinfo->stream);
> if (!cmdinfo->cmd_urb)
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + return -ENOMEM;
> cmdinfo->state &= ~ALLOC_CMD_URB;
> }
>
> if (cmdinfo->state & SUBMIT_CMD_URB) {
> - if (usb_submit_urb(cmdinfo->cmd_urb, gfp)) {
> + res = usb_submit_urb(cmdinfo->cmd_urb, gfp);
> + if (res) {
> scmd_printk(KERN_INFO, cmnd,
> - "cmd urb submission failure\n");
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> + "cmd urb submission failure (%d)\n", res);
> + return res;
> }
> cmdinfo->state &= ~SUBMIT_CMD_URB;
> }
> @@ -433,12 +463,12 @@ static int uas_submit_urbs(struct scsi_cmnd *cmnd,
> }
>
> static int uas_queuecommand(struct scsi_cmnd *cmnd,
> - void (*done)(struct scsi_cmnd *))
> + void (*done)(struct scsi_cmnd *))
> {
> struct scsi_device *sdev = cmnd->device;
> struct uas_dev_info *devinfo = sdev->hostdata;
> struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
> - int err;
> + int res;
>
> BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
>
> @@ -474,17 +504,19 @@ static int uas_queuecommand(struct scsi_cmnd *cmnd,
> cmdinfo->stream = 0;
> }
>
> - err = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
> - if (err) {
> - /* If we did nothing, give up now */
> - if (cmdinfo->state & SUBMIT_STATUS_URB) {
> - usb_free_urb(cmdinfo->status_urb);
> - return SCSI_MLQUEUE_DEVICE_BUSY;
> - }
> - spin_lock(&uas_work_lock);
> - list_add_tail(&cmdinfo->list, &uas_work_list);
> - spin_unlock(&uas_work_lock);
> - schedule_work(&uas_work);
> + res = uas_submit_urbs(cmnd, devinfo, GFP_ATOMIC);
> + UAS_DPRINTK("%s: cmd:%p (0x%02x), err:%d, state:0x%x\n", __FUNCTION__,
> + cmnd, cmnd->cmnd[0], res, cmdinfo->state);
> + if (res) {
> + usb_unlink_urb(cmdinfo->status_urb);
> + usb_unlink_urb(cmdinfo->data_in_urb);
> + usb_unlink_urb(cmdinfo->data_out_urb);
> + usb_unlink_urb(cmdinfo->cmd_urb);
> +
> + sdev->current_cmnd = NULL;
> +
> + cmnd->result = DID_NO_CONNECT << 16;
> + done(cmnd);
> }
>
> return 0;
> --
> 1.7.0.1
next prev parent reply other threads:[~2010-11-08 11:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-30 0:33 [PATCH] [USB] UAS: eliminate infinite loop; add debug print Luben Tuikov
2010-11-03 16:24 ` Greg KH
2010-11-08 11:24 ` Matthew Wilcox [this message]
2010-11-08 15:55 ` Greg KH
2010-11-08 17:27 ` Luben Tuikov
[not found] ` <272723.33242.qm-5Es2LHxk9sSvuULXzWHTWIglqE1Y4D90QQ4Iyu8u01E@public.gmane.org>
2010-11-08 17:38 ` Greg KH
2010-11-08 17:57 ` Luben Tuikov
2010-11-08 17:40 ` Michał Nazarewicz
-- strict thread matches above, loose matches on Subject: below --
2010-12-10 10:51 Luben Tuikov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20101108112456.GI4173@linux.intel.com \
--to=willy@linux.intel.com \
--cc=greg@kroah.com \
--cc=linux-scsi@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=ltuikov@yahoo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.